1. Field of the Invention
The present invention relates in general to electroluminescent panels and specifically relates to a self-contained electroluminescent back-lit clap board/slate or reusable writing board or surface that is used for the introduction of rolls, takes and scenes in the making of movies and the video films and which includes a liquid crystal clock display that is back-lit by the electroluminescent panel.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
In the making of movies and video films, where various rolls, takes, and scenes are involved, a camera assistant typically marks a slate board with a dry-erase pen to indicate the roll number, scene number, take number and other important information. The assistant, in such case, marks the clap board/slate with the appropriate information and must open the moveable arm of the clap board/slate, call attention to the operation that is about to take place, and force the moveable arm against a stationary arm to create an audio cue (soundtrack) for matching the visual cue (film/video) for editing purposes to synchronize soundtracks with scenes, takes, and the like as recorded on the clap board/slate surface. Very often the camera assistant is using such slate in a low-light or no-light situation. In the low-light or no-light situation, a slate light has been used in the past. This is a small light that requires batteries or alternating current and an operator who must try to hold the light on the clap board while it is being operated by the camera assistant. Other solutions to the problem have been the use of small flashlights by the operator. The operator attempts to keep the clap board illuminated with the flashlight or the small slate light while it is being held and operated by the camera assistant. This creates an obvious problem because the light does not evenly cover the slate and it is difficult to hold steady on the slate or clap board.
This problem was remedied in commonly assigned U.S. Pat. No. 5,457,507 which provided a self-contained electroluminescent back-lit clap board or slate or reusable writing board or surface made of transparent or semi-transparent plexiglass.TM., fiberglass or similar material that may be used with a dry-erase marking pen (overhead projector pen), fluorescent dry-erase marking pen or other nonpermanent writing utensils.
However, another important requirement that has been added to such clap boards is a time code area, the Society of Motion Pictures and Television Engineers (SMPTE) code for film and video production. The prior art clap boards utilize a high intensity one-inch tall LED readout. It has to be fed a continuous time code via cable or wireless signal.
Because one-inch tall LED devices are used for the readout, at least eight "C" batteries must be used. Clearly this creates a bulky package on the backside of the clap board and adds weight to the unit. Typical units weigh 3.3 pounds with the batteries.
It would be advantageous to have a clap board that has a time code area thereon that is lightweight and that requires low power and that would require very little space.